Start Next Child

Extract slug from title — must match /^\[(?<slug>[a-z0-9-]+)\]/. If no slug found, STOP and tell the user to add a [slug] prefix to the card title.

Extract labels from the Labels: line in the card show output. Keep only type labels: bug, chore, user, feature (case-insensitive match). Save matching labels for Phase 6.

Phase 2: Load and Parse Checklist

Find the "Steps" checklist in the card show output. If no checklist named "Steps", use the first (and only) checklist. If multiple checklists and none named "Steps", STOP and ask.

Parse each checklist item into these fields:

Phase 3: Check Migration Lock

Only needed if any unchecked item has {migrations}.

Scan for open migration children across these lists:

bin/trello list cards "In Progress"
bin/trello list cards "Done/Committed"

For each card in the output whose title matches /^\[[a-z0-9-]+\.\d{2,}\]/ (child card pattern):

bin/trello card show <card-ref>

Check the description for requires_migrations: true. If found, migrations are locked — note which card holds the lock.

Optimization: Skip the card show calls if no unchecked item has {migrations}. Also, only inspect cards matching the child title pattern.

Phase 4: Determine Ready Items

An item is READY if ALL of:

1. Not checked
2. No existing child link (no trello URL in the item text)
3. All deps are checked off (every number in its {deps:...} list corresponds to a checked item)
4. If {migrations} is true: migration lock is clear (Phase 3 found no open migration child)

Phase 5: Pick Next or Report Blocked

If a ready item exists: pick the one with the smallest NN.

If NO ready items exist: output a blocked report and STOP:

No ready items. Blocked:
- 03 blocked: deps 01, 02 not done
- 04 blocked: migrations locked by [other-slug.02] (In Progress)
- 05 blocked: deps 03 not done

Keep it short — one line per blocked item.

Phase 6: Create Child Card

Build the child card description. Goal and Note go first (the actionable content), then a --- separator, then the Lineage metadata section:

**🎯 Goal:** <step title from checklist item>

**📝 Note:** Parent card has full context; refer there.

---

### 🔗 Lineage

- **Parent:** [<parent card title>](<parent card URL>)
- **Checklist:** <checklist name> · **Item:** <NN>
- **Migrations:** <yes|no> · **Deps:** <comma-separated list or "none">

The parent link MUST be a Markdown link [title](url) — do NOT use a naked URL.

Create the card:

bin/trello card new "[<slug>.<NN>] <step title>" \
  --description "<description from template above>" \
  --list "In Progress" \
  -L "bug" -L "feature"

Include a -L flag for each type label found on the parent in Phase 1 (only bug, chore, user, feature). Omit -L entirely if the parent had none of those labels.

No need to card move separately — --list "In Progress" creates it there directly.

Phase 7: Update Parent Checklist Item

Wrap the description text in a Markdown link to the child card. The [slug.NN] prefix and any {...} tags stay unchanged — only the description becomes a link.

Before: [slug.02] Step description {deps:01} After: [slug.02] [Step description](https://trello.com/c/xyz789) {deps:01}

bin/trello checklist item-edit <parent-ref> "Steps" "<exact current item text>" "<text with description wrapped as link>"

Important: Use the exact current item text as the ITEM argument (not a position number), since item-edit matches by exact name.

Old format items: If the item uses old NN. title format, convert it to the new format at the same time: [slug.NN] [title](url) {tags}.

Phase 8: Confirm

Output:

• Child card URL
• One sentence: "Working on: [slug.NN] <step title>"
• If any items were skipped as blocked, add a short note

Example:

Created: https://trello.com/c/xyz789
Working on: [owner-data.03] Backfill job
(Skipped 02: deps 01 not done)

Red Flags

If you catch yourself doing these, STOP:

• Creating multiple child cards — Only ONE child per invocation
• Creating a child for a checked item — Checked means done
• Creating a duplicate child — If item already has a Markdown link or trello URL, skip it
• Ignoring deps — Always verify dep items are checked
• Ignoring migration lock — Always check if {migrations} items need the lock scan
• Guessing list names — Use exact names: "In Progress", "Done/Committed"
• Using position numbers for item-edit — Use exact item text as the ITEM argument
• Appending URL instead of linking — Wrap the description in [text](url), do NOT append → url or bare URLs
• Skipping the Lineage section — Every child MUST have the ### 🔗 Lineage section in its description
• Using a naked URL for parent — MUST use Markdown link [title](url) format

Quick Reference